1. Field of the Invention
The present invention relates generally to indicating devices for displaying a level line or plane, and more specifically to a leveling device which is permanently installed and adjusted on or in a movable structure, whereupon the structure may be accurately leveled by means of the present leveling device. The present level includes a two way adjustable base and an infinitesimally adjustable “bull's eye” type bubble level vial, whereby the device may be finely adjusted after installation to provide a level reference whenever the structure to which it is secured is moved.
2. Description of the Related Art
There are innumerable portable structures which require at least a close approximation of a level attitude when they are relocated periodically. Examples of such are motor homes, house trailers, and camper type vehicles. Oftentimes, a craftsman must erect a work table or the like, which requires a level attitude for accurate work. The conventional technique nearly universally used for leveling such structures is to place a level (e.g., linear or bull's eye level, electronic leveling device, etc.) temporarily on or across a surface of the structure desired to be leveled, adjust the structure until it is level according to the level instrument, and remove the instrument from the structure.
The problem with this technique is that the portable level must be repositioned on or in the structure, each time it is necessary to level the structure. In those cases where a linear level is used, the level must be repositioned at least once, normal to its initial alignment, in order to establish a level orientation for the structure. Usually, such a linear level must be repositioned back and forth a number of times along the two axes being leveled, as the adjustment along one axis will throw off a previous adjustment along the other normal axis. While such fine adjustment may not be necessary for leveling a recreational vehicle for a relatively short period of time, it may be critical for a work table or the like, where extreme precision is required.
In some instances, people have secured conventional level instruments to the structure in order to avoid the need to position and reposition a level or levels temporarily on the structure, each time it must be leveled. However, conventional levels have no adjustability built into them, as their bases are immovably fixed relative to the level indicator (bubble, etc.) display. This results in a great deal of difficulty in accurately positioning such a conventional level in a permanent attachment. While such levels can be shimmed and otherwise adjusted before being permanently secured in place, the very act of securing them (e.g., driving screws, applying adhesives, etc.) is often sufficient to induce some slight variance between true level and the level indicator. The user of the structure must thereafter always compensate for the error induced.
The present invention provides a solution to the above problem, by means of a level instrument which is configured for permanent attachment to a movable or portable structure, and which provides for multiple axis adjustment to fine tune the device after installation. This assures that once the structure has been leveled, that the present level indicator can also be precisely leveled along or across multiple axes, with the present level device always providing a true indication of level (or deviation therefrom) for the structure to which it has been permanently secured.
A discussion of the related art of which the present inventor is aware, and its differences and distinctions from the present invention, is provided below.
U.S. Pat. No. 4,829,676 issued on May 16, 1989 to David C. Waldron, titled “Hands-Free Level Indicating Device,” describes a conventional linear bubble or spirit level which has been modified with a slot at each end thereof, with a generally U-shaped clamp being placed in each slot. This configuration allows the level to be temporarily clamped to a wide number of different elongate objects (pipes, joists, etc.). Waldron does not provide any means of permanently attaching the level to a structure to be leveled, nor does the level include any means for adjusting its attitude after installation or attachment to another article or object. Moreover, the Waldron level cannot be used to provide an omnidirectional display of the level of a surface, as can the bull's eye level used with the present multiple axis installable and adjustable level.
U.S. Pat. No. 5,163,229 issued on Nov. 17, 1992 to Giovanni F. Cantone, titled “Plumb And Horizontal Locating Device,” describes a pendulum type leveling instrument having a light beam therein to project a vertical or horizontal beam of light, depending upon the embodiment. Cantone does not disclose any means of permanently attaching his level to another object or structure, nor for adjusting the level of the base relative to the structure upon which it is place or attached. Moreover, the configuration of the Cantone level would require that the plumb bob be removed whenever the structure is moved. Precise replacement of the plumb bob would not be possible, due to minor variations in position while placing the plumb bob on its two mutually normal support rods.
U.S. Pat. No. 5,174,034 issued on Dec. 29, 1992 to Richard L. Swanda, titled “All-Purpose Level,” describes a level which extends normal to a pair of hinge leaves. The device is adapted for use in determining the verticality of corners and the like, wherein the two leaves are extended along each side of the corner and the level is read to determine if the leaves, and therefore the sides which define the corner, are perpendicular. While the Swanda device uses hinge leaves, the leaves have no holes therethrough to permit the permanent attachment of the device to a structure; it must be held in place. Moreover, Swanda does not provide any form of adjustment for his level. In the event that it were to be attached to a non-vertical surface (or non-horizontal, in some embodiments), the level could not be adjusted to indicate level for the remainder of the structure.
U.S. Pat. No. 5,402,579 issued on Apr. 4, 1995 to Robert K. Smith, titled “C-Clamps With Integral Bubble Levels,” describes a linear bubble type level permanently and immovably affixed to the back or spine of the C-clamp; no adjustment is possible. The Smith level and C-clamp combination can only be temporarily secured to a relatively thin and substantially vertical panel, to check the verticality of the panel. Smith provides no means for permanently securing a level to one side or surface of a panel, or for adjusting the level indicator after installation to match it to a true horizontal reference, which features are parts of the present invention. Moreover, the Smith device cannot utilize a bull's eye type level, as the leveling of the C-clamp about its clamping axis is arbitrary.
U.S. Pat. No. 5,406,713 issued on Apr. 18, 1995 to Robert Oman et al., titled “Apparatus For Maintaining A Scientific And Measuring Instrument Or The Like In A Level Plane,” describes a tripod with a central column normal to the plane of the legs. A pendulum type device is disposed within the column, and determines the verticality of the column (and hence the horizontal attitude of the legs) by contact with contacts disposed upon the inner walls of the column when the column is not vertical. Contact results in the operation of one or more motors at the feet of the device in order to level the device automatically. The Oman device cannot be permanently installed upon a surface that is other than very close to horizontal, and no adjustment for the level means relative to the remainder of the tripod structure is provided. No visual level indication is provided.
U.S. Pat. No. 5,421,094 issued on Jun. 6, 1995 to David W. McCord, titled “Adjustable Level,” describes an angle having a bull's eye type level secured to a plane normal to both arms of the angle. The device is primarily adapted for temporary placement along a pipe or column, to check the verticality of the pipe; no permanent attachment means is provided. While the plate upon which the bubble level is mounted can be turned to allow the device to check angles other than vertical, the bubble level adjustment is only in a single plane, and only for a relative few angles. McCord does not provide infinitesimal adjustment of his bubble level in two mutually perpendicular dimensions relative to the body of his device, whereas such infinitesimal, bidimensional adjustment is a part of the present invention.
U.S. Pat. No. 5,628,521 issued on May 13, 1997 to Robert H. Schneider et al., titled “Manually Operated Vehicle Leveling System,” describes the installation of a series of hydraulic jacks in a recreational vehicle or the like. Schneider et al. recognize the desirability of leveling such vehicles when parked and used as living quarters, but only disclose the actual physical leveling system. The only means of measuring or checking the level of the vehicle mentioned by Schneider et al., is the use of a conventional, temporarily placed, portable bubble level (column 6, lines 10 and 11). Schneider et al. do not disclose any form of permanently mounted level indicator which is adjustable to match the level indicator with the true level of the structure after installation, as provided by the present invention.
U.S. Pat. No. 5,839,200 issued on Nov. 24, 1998 to Dominic Decesare, titled “Multi-Function Horizontal And Vertical Alignment Tool,” describes a temporarily installable (no permanent mounting means are provided) bull's eye level, wherein the level is mounted upon an arcuately adjustable bracket secured to the elongate level body. The adjustment is only in a single plane, rather than being bi-directional, as in the case of the present level device. Moreover, Decesare provides only five different positions for his level adjustments relative to the level body. In contrast, the present level device is infinitesimally adjustable in any direction(s) defining a leveling plane, and in addition includes coarser initial adjustments which may be performed during the installation to permit the device to be permanently secured to virtually any surface, regardless of its angle or slope.
U.S. Pat. No. 6,131,298 issued on Oct. 17, 2000 to William McKinney et al., titled “Self-Supporting Level Measurement Device,” describes an otherwise conventional multi-tube bubble level having a spring clamp removably secured to each end thereof. The clamps are used to temporarily secure the level to another structure, e.g., a framing stud, etc., to check the verticality thereof during construction. The clamps secure to the level body by means of square retaining studs in the manner used to secure a socket to the drive of a ratchet wrench. No means for permanently mounting the device to a surface, or for precisely adjusting the level vials relative to the body of the device after such installation, are disclosed by McKinney et al.
U.S. Pat. No. 6,332,277 issued on Dec. 25, 2001 to Greg J. Owoc et al., titled “Level With Securing Apparatus,” describes an otherwise conventional level with a number of embodiments of devices for securing the level temporarily to another structure (framing stud, pipe, etc.). The various temporary securing means comprise clamps, straps, surrounding bands, etc. None of the securing means provides for the permanent attachment of the device to a generally planar surface, as does the present level indicator invention. Owoc et al. do not provide any means of adjusting the angles of the level vials within the conventional level body of their device. The Owoc et al. level is felt to resemble the level of the '298 U.S. Patent to McKinney et al. more closely than it does the present invention.
U.S. Pat. Publication No. 2001/25,426 published on Oct. 4, 2001, titled “Leveling Instrument-Clamping Device,” describes a specialized attachment mechanism for temporarily securing a surveyor's precision level to the top of a tripod. As such, the mechanism cannot be permanently secured to a generally planar surface, as provided by the present invention. Moreover, the level device disclosed in the 426 publication is not a component of the mechanism for which a patent is sought. Rather, the level adjustment mechanism merely provides an interface between an existing, conventional surveyor's level or the like, and the conventional tripod to which such levels are conventionally mounted for temporary use in the field.
U.S. Pat. Publication No. 2002/174,553 published on Nov. 28, 2002, titled “Adjustable Level,” describes a three way tubular bubble level permanently and immovably attached to a pipe clamp type mechanism. The level body cannot be adjusted relative to the clamp mechanism, and no means is provided for permanently attaching the device to a generally planar structure, as provided by the present level.
U.S. Pat. Publication No. 2003/93,909 published on May 22, 2003, titled “Level Having A Detachable And Quick Release Structure,” describes an insert for removable installation in a conventional level frame, for holding a small line level in the level frame. No means for permanently mounting the level to another surface, or for adjusting the level relative to the level frame, are provided.
Finally, Japanese Patent Publication No. 7-292,865 published on Nov. 7, 1995, titled “Base Piece With Circular Level,” describes (according to the drawings and English abstract) a bracket for permanently imbedding within a concrete slab or the like. The bracket includes a U-shaped upper portion, to which a bull's eye level may be secured. No means for mechanically fastening the device to a generally planar panel, or for bidirectionally adjusting the level of the bubble level, is apparent.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed. Thus a multi-axis installable and adjustable level solving the aforementioned problems is desired.